I have patched the savage driver so it exposes modes with non-zero alpha depth. The patch only changes the modes which the driver exposes, I have not verified that all exposed modes are actually functional. Using the patched driver clutter applications are functional (within the constraints of the hardware of course) and the segfaults disappear. The patch applies to mesa-7.7 as used in Lucid. Again, this patch makes clutter apps work but I have not verified that all exposed modes are actually supported by the driver and the hardware. This is the mode table after applying the patch according to glxinfo on a 24 bit framebuffer: 24 GLX Visuals visual x bf lv rg d st colorbuffer ax dp st accumbuffer ms cav id dep cl sp sz l ci b ro r g b a bf th cl r g b a ns b eat ---------------------------------------------------------------------- 0x21 24 tc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x22 24 dc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x92 24 tc 0 32 0 r . . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x93 24 tc 0 32 0 r . . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x94 24 tc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x95 24 tc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0xa2 24 tc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0xa3 24 tc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0xa4 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0xa5 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0xa6 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0xa7 24 tc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0xb4 24 dc 0 32 0 r . . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0xb5 24 dc 0 32 0 r . . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0xb6 24 dc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0xb7 24 dc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0xb8 24 dc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0xc5 24 dc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0xc6 24 dc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0xc7 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0xc8 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0xc9 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0xca 24 dc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x43 32 tc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 Ncon 24 GLXFBConfigs: visual x bf lv rg d st colorbuffer ax dp st accumbuffer ms cav id dep cl sp sz l ci b ro r g b a bf th cl r g b a ns b eat ---------------------------------------------------------------------- 0x4a 0 tc 0 32 0 r . . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x4b 0 tc 0 32 0 r . . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x4c 0 tc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x4d 0 tc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x4e 0 tc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x4f 0 tc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x5c 0 tc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x5d 0 tc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x5e 0 tc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x5f 0 tc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x60 0 tc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x61 0 tc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x6e 0 dc 0 32 0 r . . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x6f 0 dc 0 32 0 r . . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x70 0 dc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x71 0 dc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x72 0 dc 0 32 0 r y . 8 8 8 8 0 24 8 0 0 0 0 0 0 None 0x73 0 dc 0 32 0 r y . 8 8 8 8 0 24 8 16 16 16 16 0 0 Slow 0x80 0 dc 0 24 0 r . . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x81 0 dc 0 24 0 r . . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x82 0 dc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x83 0 dc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow 0x84 0 dc 0 24 0 r y . 8 8 8 0 0 24 8 0 0 0 0 0 0 None 0x85 0 dc 0 24 0 r y . 8 8 8 0 0 24 8 16 16 16 0 0 0 Slow